What we know about the Moscow concert hall attack

By Lauren Said-Moorhouse, CNN (CNN) — Russia has been left reeling in the wake of the nation's worst terrorist attack in decades. Nearly a dozen people have been detained in connection with the massacre, which saw armed assailants storm a popular concert venue complex on the outskirts of the capital, killing more than 130 people. Here's what we know. What happened? Attackers armed with guns and incendiary devices opened fire at random at the Crocus City complex - home to both a popular music hall and shopping center - on Friday night. Crowds were still filing in but the auditorium…